This application relates to weather radar systems. More particularly, this application relates to weather radar system having improved performance.
Weather radars are known in the art for detecting and displaying severe weather to a crew in an aircraft on a two-dimensional map display showing range, bearing, and intensity of a detected weather system, which may be convective or stratiform in nature. Flight hazards due to weather conditions are primarily the result of precipitation and turbulence. Airborne weather radars have been optimized to detect rain.
As weather radars become more sensitive and process previously stored sampled state information, other aircraft are being detected and displayed to flight crews when not desired. Newer radars use longer transmitter pulse widths that make the problem worse since the length of the radar return from aircraft on the radar display is not substantially different from the radar return length as produced by a small area weather feature.
A spurious aircraft may appear as multiple images on a weather radar system display due to storage of the target echo in internal memory and the motion of the spurious aircraft. Having a weather display with spurious aircraft displayed is undesirable since it may lead to difficult decision making about the weather and the spurious aircraft motion.
In addition, next generation radar systems, such as wind shear radar systems, are utilizing smaller antennas. Smaller antennas generally have a larger beam width. Accordingly, such systems can be more susceptible to receiving ground clutter.
Thus, there is a need for a reliable low-cost system for detection and removal of spurious aircraft and/or ground clutter from a weather radar display. Further, there is a need for a weather radar system that can utilize smaller antennas and yet achieve suitable performance. Further still, there is a need for a weather radar having variable loop gain and resolution with point target editing capability. Yet further still, there is a need for a weather radar system that can utilize a pulse compression and demodulation with code technique to achieve the advantages of both compressed pulse lengths and long pulses. Further still, there is a need for a reliable system capable of distinguishing between volume targets and point targets. Yet further still, there is a need for a weather radar system that achieves the advantages of high resolution and high loop gain.